A number of issues affect the performance of a high density microelectronic package. Many of these are related to die attach technology. One example is thermal management, and particularly concerns over thermal heating and stress due to differences in the coefficient of thermal expansion (CTE) in different adjacent materials assembled in the package. Internal stress at the chip level as well as at the circuit board level can affect the electronic performance of a microelectronic package.
MEMS and IC devices may require stress relief for die attach at the device level as well as at the board level. Stress relief may be achieved by mechanical compliance at the attachment points. Examples of mechanically compliant adhesives are silicones, epoxies, and polyimides. Silicone adhesives are popular compliant prior art die and board attach adhesives and may be employed in the form of silicone dots positioned at attachment points. If stand-off is an issue, silicone dots alone may not control the stand-off of a device from a substrate. If the stand-off provided by the silicone dots varies, the stress imparted to the die or board may vary by how much silicone touches the back side of the device. A prior art method to control the stand-off height is to incorporate glass beads in the silicone adhesive. An improved method to control the stand-off with silicone dot adhesives for die attach would be helpful.